How Ebay could be improved...

There are a handful of frustrating things about ebay that could easily be resolved:

Have Knock Bidding To Prevent Auction Sniping
This happens because Ebay has a fixed timed auction where an auction must end at a particular time. This means bids made right at the very end of an auction period cannot be outbid.
A seller can nominate to include this bidding process into their sale. It improves their likelihood of having bigger bids and is fairer for bidders who now do not get sniped as truly you get the highest bid.
When an auction comes to an end: the knock period (when the auctioneers gavel hits the desk) in the case of Ebay this might be 5 minutes, the highest bidder at the point of entering the knock period and other bidders that place bids in this period get an extended period of bidding so that the auction can end effectively. Bidders can then be contacted by SMS or email so that they can enter the knock bidding process. Once all prospective bidders have entered (they have 15 minutes to do so), then they enter into a period of further bidding which entails each counter bid being made within 5 minutes. If there is no counter bid, the bidding ceases and the auction ends on the highest bid.
This is possible, because after Ebay being around now for so long, communications technology is such that now people are more connected.
Snipers by the way still have the ability to enter the knock period - its just the snipe facility can now maintain the highest bid and bid on their behalf at the 5 minute intervals.
Some Ebayers could also enter the Knock period who have not necessarily been invited.

Ebay should allow one to adjust their highest bid.
Once you have placed your highest - even though you are currently winning with a lower bid - you should be able to adjust it downwards to your current winning bid i.e. drop out at the next bid.
At the moment Ebay does not allow you to do this. This could also stop snipe sites doing their work if only Ebay would allow this flexibility, people wouldn't need the services of snipe to manage their bidding correctly.